1995 p38 2.5 judder / misfire

Advice and input would be appreciated please, my 95 p38 2.2 has started juddering at certain speeds and misfiring, as a first port of call I replaced the fuel filter, which seemed to improve things for a week or so but the problem is getting worse, car starts ok, no smoke or rattles pulls ok and cruises ok but at around 40-45 I get the juddering/misfire, (id describe it as it feels like a plug lead breaking on the old mini's!!) I have had the car 18 years and the pump and injectors have never been touched or given any problems until now.

I have checked with nanocom with the engine at working temp and at idle and have the following information from the screens:

start fuel(mg/str 32.00
fuel quantity feedback 63.75
fuel quantity current. 6.00
fuel quantity compared. 26.50
fuel temp 35.24
SWG setpoint. 3200.00
SWG actual. 2780
inj. set point (deg). 1.80
inj actual (deg). 1.75
timing modulation (%) 75.26. (it fluctuates around this number but not by much)
idle rpm. high
low idle. high
needle rpm 728.00
crank speed rpm. 750.75
road speed 0

When I go to outputs and select timing solenoid it makes no difference to the engine and when I try it with engine off and ignition on I don't hear anything from injector pump

I don't have any engine working light on
I have downloaded the information from blackbox which suggests a timing modulation setting remaining steady at between 45% and 55% so I am leaning towards thinking it the injector pump starting to play up but I am no diesel injection expert

Are you sure it's actually a miss fire and not a UJ breaking up?
How full is you fuel tank? If the tank is low and the lift pump is failing fuel starvation might come into play.
The modulation is way out, really need the Nanocom reading of engine temperature to know exactly. With the engine at 95C the modulation should be 50%, you cannot go by the gauge on the dash as the needle will be at 12 o'clock from about 85 to 105C
FIP is probably OK but the timing chains have stretched affecting the FIP timing and modulation which is normal, this can easily corrected.
I think you will find your P38 is a 2.5 not a 2.2

Thanks Data ,its defiantly misfire, all the u/j's were done 18 months ago and are regularly greased,
the engine temp was at 81.48 at the time of looking with nanocom
air temp 27.07
boost pressure 100.05
ambient pressure. 100.05
throttle pot %. 0.00
throttle pot v. 0.3
all the above readings taken at idle
I have noticed over the last week the idle speed cant make its mind up sometimes 1000 rpm then drops to around 750 and this can be with the engine hot or cold
as I mentioned earlier when I test the timing modulation with nanocom function I hear nothing from pump with key on engine off and with engine running when I again try the modulation function it makes no difference to the engine
I always keep the tank at least 1/4 full and you are correct regarding the engine being 2.5 my bad a combination of dyslexia and fat fingers!
I take on board what you say regarding the chains stretching but if so would have expected them to last longer than 113949 miles which is all the car has done even though its elderly and over the years I have had it the oil and filters have been changed yearly regardless of what milage I have done,
With chain stretch in mind I had considered marking the position of the pump as a reference and then then adjusting it a little to see if it improves the issue?
I had also considered the possibility of the in tank pump but as the car will pull drive well when driven hard it makes me think its getting a strong supply of fuel to the injection pump?

steveshone said:

Thanks Data ,its defiantly misfire, all the u/j's were done 18 months ago and are regularly greased,
the engine temp was at 81.48 at the time of looking with nanocom
air temp 27.07
boost pressure 100.05
ambient pressure. 100.05
throttle pot %. 0.00
throttle pot v. 0.3
all the above readings taken at idle
I have noticed over the last week the idle speed cant make its mind up sometimes 1000 rpm then drops to around 750 and this can be with the engine hot or cold
as I mentioned earlier when I test the timing modulation with nanocom function I hear nothing from pump with key on engine off and with engine running when I again try the modulation function it makes no difference to the engine
I always keep the tank at least 1/4 full and you are correct regarding the engine being 2.5 my bad a combination of dyslexia and fat fingers!
I take on board what you say regarding the chains stretching but if so would have expected them to last longer than 113949 miles which is all the car has done even though its elderly and over the years I have had it the oil and filters have been changed yearly regardless of what milage I have done,
With chain stretch in mind I had considered marking the position of the pump as a reference and then then adjusting it a little to see if it improves the issue?
I had also considered the possibility of the in tank pump but as the car will pull drive well when driven hard it makes me think its getting a strong supply of fuel to the injection pump?

Click to expand...

At 81C, modulation should be around 40%, it varies a bit according the the firmware level in the EDC.
What would you expect to hear from the FIP? You cannot "test modulation" with Nanocom,, you can only read the live data.
Crap German engineering means that by 80K miles the chains will be stretched, how much seems to be pot luck depending on quality of servicing, oil and type of use.
To avoid bacterial growth due to condensation in diesel tanks, in winter especially, it's best to keep the tank full, if you get diesel bug it can cause rough or no running. As your tank is low, do a flow test on the lift pump.

thanks again Data, I found this on the information from nanocom site:

1. BOSCH EDC - Diagnostic Capabilities (Outputs)
   
   This is a choice of outputs that can be tested. Click on the each option to activate the output for 30 seconds.
   
   • Timing Solenoid: This triggers the timing solenoid which is mounted on the Injector pump. It should be heard ticking.
     

I meant to add there is a page in nanocom regarding pump calibration, it has no figures in it just blank boxes apart from one at bottom saying 128 which I think relates to engine speed and at the bottom a button to write settings, should this page actually show the pump calibration settings??

what are your thoughts on marking the pump position as a reference and then adjusting the pump timing, and would I be correct in thinking I would need to turn the top of the pump towards the engine ??

steveshone said:

thanks again Data, I found this on the information from nanocom site:

1. BOSCH EDC - Diagnostic Capabilities (Outputs)
   
   This is a choice of outputs that can be tested. Click on the each option to activate the output for 30 seconds.
   • Timing Solenoid: This triggers the timing solenoid which is mounted on the Injector pump. It should be heard ticking.

I meant to add there is a page in nanocom regarding pump calibration, it has no figures in it just blank boxes apart from one at bottom saying 128 which I think relates to engine speed and at the bottom a button to write settings, should this page actually show the pump calibration settings??

what are your thoughts on marking the pump position as a reference and then adjusting the pump timing, and would I be correct in thinking I would need to turn the top of the pump towards the engine ??

Click to expand...

The only solenoid in the FIP I have ever heard is the stop solenoid.
All the boxes should have figures. 128 in the first box controls idle speed. I can give you a typical set figures to write to the other boxes.
I have a method of re-timing the FIP without the DTI, I will PM you details if you wish.

any information you could send would be greatly appreciated thank you

A misfire could be a cps failing when it warms up A bit .....

cps? please explain

Crown prosecution service DOH i mean crank position sensor

thanks for that, driving with nanocom plugged in and with the fault prevalent the crank reading and the injector needle lift sensor remain roughly the same

steveshone said:

thanks for that, driving with nanocom plugged in and with the fault prevalent the crank reading and the injector needle lift sensor remain roughly the same

Click to expand...

Can you see them changing if you rev it?

Hi Grrrrrr,
sorry for late reply I haven't had time to do anything else with it at the moment, and will probably be after Christmas now, the latest development is the fuel gauge reading when it feels like, it either shows what's in the tank or needle on the empty stop but I guess as the pump sender unit is 26 years old its reaching its sell by date and to be expected, if I give the car a good rocking with the steering wheel as I drive along it springs back into life for a while, replacing it should cure the fuel gauge issue and a new pump will be more efficient than the old one even if its not related to the misfire/judder, but I doubt that will be the cause or cure of the timing modulation issue, when I get time I will adjust the FIP as Data suggested and see how things go
best regards,
Steve

Get a VDO lift pump if you can. The £40 jobbies are not great.